The Sufficient (Vol 5) · Hadith 1695 (#Ḥadīth #3)

3- مُحَمَّدُ بْنُ إِسْمَاعِيلَ عَنِ الْفَضْلِ بْنِ شَاذَانَ عَنْ صَفْوَانَ بْنِ يَحْيَى عَنِ الْعَبْدِ الصَّالِحِ قَالَ قُلْتُ لَهُ أَرْضَعَتْ أُمِّي جَارِيَةً بِلَبَنِي قَالَ هِيَ أُخْتُكَ مِنَ الرَّضَاعِ قَالَ فَقُلْتُ فَتَحِلُّ لأخِي مِنْ أُمِّي لَمْ تُرْضِعْهَا بِلَبَنِهِ يَعْنِي لَيْسَ بِهَذَا الْبَطْنِ وَلَكِنْ بِبَطْنٍ آخَرَ قَالَ وَالْفَحْلُ وَاحِدٌ قُلْتُ نَعَمْ هِيَ أُخْتِي لأبِي وَأُمِّي قَالَ اللَّبَنُ لِلْفَحْلِ صَارَ أَبُوكَ أَبَاهَا وَأُمُّكَ أُمَّهَا.

3. Muhammad ibn ‘Isma’il has narrated from al-Fadl ibn Shadhan from Safwan ibn Yahya who has said the following: “This is concerning my question before Allah’s virtuous servant , about the case of my mother who has breastfed a girl along with me. He (the Imam) said, ‘She is your sister of breastfeeding.’ I then asked if she is lawful for my brother from my mother’s side whom she has not breastfed with his milk, that is not from this pregnancy but from another pregnancy. He (the Imam) asked, ‘Is the ‘impregnating agent’ (husband) one?’ I replied, ‘Yes, she is my sister from my parents.’ He (the Imam) said, ‘Because of the milk of “impregnating agent” your father has become her father and your mother her mother.’”

Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).